[jira] [Assigned] (TEZ-1248) Reduce slow-start should special case 1 reducer runs

["Zhiyuan Yang (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/TEZ-1248?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Zhiyuan Yang reassigned TEZ-1248:
---------------------------------

    Assignee: Zhiyuan Yang

> Reduce slow-start should special case 1 reducer runs
> ----------------------------------------------------
>
>                 Key: TEZ-1248
>                 URL: https://issues.apache.org/jira/browse/TEZ-1248
>             Project: Apache Tez
>          Issue Type: Improvement
>    Affects Versions: 0.5.0
>         Environment: 20 node cluster running tez
>            Reporter: Gopal V
>            Assignee: Zhiyuan Yang
>            Priority: Critical
>
> Reducer slow-start has a performance problem for the small cases where there is just 1 reducer for a case with a single wave.
> Tez knows the split count and wave count, being able to determine if the cluster has enough spare capacity to run the reducer earlier for lower latency in a N-mapper -> 1 reducer case.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)